This invention relates to a new oxygen stabilized intermetallic compound and to a method of storing hydrogen using that compound. More specifically, this invention relates to a new oxygen stabilized zirconium-vanadium intermetallic compound, to a method of storing hydrogen and to a method of separating hydrogen from other gases using that compound.
Hydrogen for use as a fuel or as a raw material may be produced by the steam reforming of a hydrocarbon such as coal or it may be formed in waste gas streams resulting from the processing of hydrocarbons such as crude oil. In either situation, the hydrogen is found mixed with other gases which may include CO, CO.sub.2, O.sub.2, N.sub.2 and water vapor.
In order to utilize the hydrogen, it is necessary to separate it from the other gases. One present commercial process for hydrogen separation utilizes palladium films in which at about 320.degree. C. molecular hydrogen dissociates to atoms on palladium which after diffusion through the palladium, recombine on the opposite side of the film to form pure hydrogen. While this method is very efficient and effective, it is also very expensive.
The use of adsorbants which are selective for hydrogen over other gases has also be suggested. In U.S. Pat. No. 3,793,435, Feb. 19, 1974, the use of LaNi.sub.y Cu.sub.5-y, where Y=1 to 4, selectively to absorb hydrogen from other gases is described. However, depending upon the amount of copper, the material is effective for sorbing hydrogen in the presence of no more than about 4% CO. The separation of hydrogen from a hydrogen-methane mixture using Fe.sub.x TiNi.sub.1-x is described on pages 981-986 of the Proceedings on the 12th Intersociety Energy Conversion Engineering Conference (1977). However, it was brought out that CO.sub.2 interferes with the sorption and that CO.sub.2 and similar impurities will either have to be removed or a sorbant showing no interference to impurities in coal-derived gases will have to be developed.
Thus, insofar as is known, there are no sorbants which are completely satisfactory for the selective sorption of hydrogen from a stream of mixed gases.